基于UDE的虚拟同步发电机功频振荡抑制策略

针对分布式发电并网逆变器采用虚拟同步发电机(VSG)技术引起的功频振荡问题,提出基于不确定性和扰动估计器(UDE)的功频振荡抑制策略。对功角稳定机理以及功频振荡特性进行深入分析,建立基于不确定性和扰动估计器的有功环振荡抑制控制模型。该控制方法将外部扰动和不确定性用集总扰动来代替,采用一阶低通滤波器对该集中扰动进行估计,利用滤波带宽思想实现对功频振荡的抑制效果,具有较好的系统鲁棒性。最后,通过时域仿真实验验证了所提振荡抑制策略的有效性。

POWER-FREQUENCY OSCILLATION SUPPRESSION STRATEGY OF VIRTUAL SYNCHRONOUS GENERATOR BASED ON UDE

A power frequency oscillation suppression strategy based on uncertainty and disturbance estimator （UDE） is proposed to solve the problem of power frequency oscillation caused by virtual synchronous generator （VSG） technology in distributed generation grid-connected inverter. The power angle stability mechanism and power frequency oscillation characteristics are analyzed in depth, and the active loop oscillation suppression control model based on UDE is established. The control method replaces the external disturbance and uncertainty with lumped disturbance and the first-order low pass filter is used to estimate the lumped disturbance. The filtering bandwidth idea is used to suppress the power frequency oscillation, which has good system robustness. Finally, the effectiveness of the proposed oscillation suppression strategy is verified by time domain simulation experiments.